by Roger Gilroy (Transport Topics) Diesel fuel still has a large role to play in achieving greater emissions reductions in heavy-duty trucks, experts said during a recent conference in San Francisco. Separately, they urged more in-use testing of engines to verify the gains, and increased use of renewable diesel, which is chemically similar to petroleum diesel, but cleaner.

While more progress is needed, the trucking industry has come a long way over the past 30 years, one industry executive said. He noted it would take 60 trucks with 2010 engines — which were the first to drastically slash discharges of particulate matter and nitrogen oxide — to equal the emissions of one truck from 1988.

“I think that is a good story,” said Tim Blubaugh, executive vice president of the Truck & Engine Manufacturers Association (EMA).

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Plus, greater use of renewable diesel fuel would help improve air quality, a fuel company executive said.

Another expert said renewable diesel could help reduce emissions even on pre-2010 engines.

“It is diesel fuel. It is certified as [ultra low-sulfur diesel] as well as CARB-certified diesel. But it is produced not from fossil crude oil, rather 100% renewable and sustainable raw materials,” said Dayne Delahoussaye, head of North American Public Affairs at Neste — the world’s largest producer of renewable diesel refined from waste and residues.

You can take oils, fats and greases, he said, and purify and refine them into a hydrocarbon molecule, the same molecule as traditional diesel except much cleaner — a clear fuel. “When you have control of your materials coming in, you can have a much more consistent and cleaner product,” he said.

Delahoussaye added that renewable diesel is not biodiesel, which is processed differently.

Biodiesel is produced only from lipids — such as vegetable oils, animal fats, grease and algae. Renewable diesel is produced from lipids and cellulosic biomass, such as crop residues, woody biomass and dedicated energy crops, according to the U.S. Department of Energy.

Delahoussaye said renewable diesel has a higher cetane number than fossil diesel. Cetane in diesel is somewhat analogous to octane in gasoline, with higher amounts required in certain engines.

Renewable diesel could be used in pre-2010 engines, too, he said. “There’s nothing you need to do to switch,” he said. READ MORE